This is a file package that will allow you to create fully functional retracting bow planes for boats such as the USS Nautilus (SSN571) and the US Gato/Balao Class. 
 
The files were specifically generated for the file package for the 571 Nautilus in 1/72 scale, but could be modified to suite almost any boat with this form of bow retracts. 
 
Originally deisgned by Bill DiMartino, these print out to form a beautifula and smoothly operating assembly. While photos show the use of a waterproof servo, you could easily use a rotary shaft from a servo inside your watertight cylinder as well. 
 
See video of repeating servo test of the prototype of this design